Pitman-connection



(No Model.) 1 2 Sheets-Sheet 1.

F. FORBES.

PITMAN CONNECTION No. 398,717. Patented Feb. 26, 1889;

fzaezzfof 257696 UNITED STATES PATENT OEETCE.

FRANK FORBES, F ANS 'lAR, IOWA.

PlTMAN-CON N ECTION.

SPECIFICATION forming part of Letters Patent No. 398,717, dated February 26, 1889. Application filed October 25, 1886. serial No. 217,188. (No model) ToaZZ whom it may concern.-

Be it known that I, FRANK FORBES, of St. Ansgar, in the county of Mitchell and State of Iowa, have invented a new and useful Improvement in Pitman Conneetions for I\Iowing-Maehines with Tilting Bar, or those machines upon which the guards can beiilted or oscillated at the will of the operator upon an axis parallel with the cutter-bar and independent of the gear-frame to which the crankwheel is attached, of which the following is a specification. I

My object is to provide a simple form of pitman-connection for the reciprocating knifehead of mowing-maehines, such as will allow 'for the pivotal movement of the pitman as it is moved by the crank-wheel, and also for the tilting movement of the knife-head and cutter-bar indepei'identot' the pitman. Subordinate to this object, I aim to provide a broad, Hat, and substantial bearing for the pitman, in the knife-head, to make such bearing removable, whereby it may be replaced when worn, to avoid the use of screws, belts, or rivets in, connecting the pitman to the knifehead, and to provide a guide and holdingplate which will retain the pitman in place at whatever angle the knife-head maybe tilted.

\Vith these objects in view my invention consists of a hollow knife-head having its ver- 7 tical sides at a distance apart equal to the width of the bearing end of the pitman, where by a snug joint is provided to prevent lost motion, and having its upper and lower sides cut away to provide for the tilting action of the cutter-bar and knife without interfering with the pitman.

I urther, it consists of a hollow knife-head having its e1)ening formed to permit tilting movement and to prevent lost motion of the pitman, a removable bearing-box having a cylindrical opening, and a pitman adapted thereto. In combination with the tilting cutter-bar having a hollow head to receive the pitman, a retainer or guide is employed to keep the pitman end. in place within the head, and this feature constitutes a further portion of my invention.

The details of construction by which I am enabled to reduce the invention to practical and successful form also form a part of this invention.

be inserted within the hollow head.

In the drawings, Figure l a perspective view of the hollow knife-head with the means for adjusting the size of the opening therein. Fig. 2 represents the n'lovable partition-wall used within the head for the bearing of the pitman. Fig. shows the adj Listing-wedge. Fig. i shows the bearing'box for the pitman. Fig. 5 shows the pitman; Fig. 6, the guide or retain ing-piece for the pitman. Iiig. 7 is a central vertical section through the knifehead and the pitman-bearing. Figs. 8, 9, and 10 show modified forms, each of which embodies the essential features of my invention.

Referring to the drawings, ll represents the knife-heath which is made hollow to aitord a bearing for the o iierating-pitman. The vertieal sides of this head, as in Fig. l, are made flat and broad to aiiord a substantial bearing for the pitman-bearing end. The head may be formed with its walls at such a distance apart as to provide a support for the pitma-n end; but I prefer to employ a movable bearing-wall, c, Fig. l, by which the wear maybe taken up and the head adapted to the size of the pit man end. This bearing-wall cis formed with a vertical. and inclined side. For adjusting and holding the bearing-wall c, I use a wedge, (l, which has one side adjacent to and corresponi'ling to the inclined side of wall c, against which it bears.

A screw, e, passes through the knife-head, and its end engages with the sides of notch f in the wedge (I, so that as the screw is adjusted up or down it moves the wedge and determines the position oi the bearing-wall c. By this vertical bearing-wall a good bearing is afforded, and by adjusting the wall 0, or properly fitting the parts, all lost motion and play will be avoided. The pitman I is provided with a right-angular extension, 0, which constitutes the bearing end, and is adapted to It is provided with abearing piece or box, B,whieh is adapted to lit; snugly within the bearingsides of the hollow head, and istherefore pro-- vided with correspondingly-shaped sides.

An opening, on, is formed to receive the eylindrical extension 0, and by this construction it will be seen that the pitman is free to have the pivotal movement which arises from the movement of the crank-wheel. If desired, the extension 0 may be used without the bearingbox; but the omission of this element causes the loss of an advantageous function, and hence is in no sense desirable. The top and bottom portions of the hollow head are cut away, as shown in Figs. 7 and 8, to allow for the tilting action of the cutter-bar and knife without interfering with the pitman.

In Fig.7 the axis upon which the knife tilts is in line with the point or edge a, which is the lower contact-point between the bearingbox B and the knife-head. From this point the bottom of the head is cut away, in order that the cutter-bar and head may be tilted freely. For the same purpose the top of the head is cut away from the point or at any suitable angle. On the bearingbox a curved bearing-surface, 2', is formed, the curve being struck from the axial point a as a center, and as the head tilts the contact between the head H and the box is preserved, the point or edge or passing over the curved surface '2'. The bearing-box is provided with retaining-lugs Z, curved 011 their lower faces to fit the curved bearing-edges b b of the knife-head walls. The curve of the edges b is also made from the axial point a as center. These lugs serve to retain the bearing-box in proper position, the lugs Z being in constant contact with the curved edges Z). Especially do they serve to prevent movement of the box through the head and away from the pitman, and as the opening m extends only partially through the box a positive bearing is afforded for the end of the pitman, which prevents lateral play.

In Fig. 8 the axial line and bearing-edge a are at the top of the box B, and the positions of the curved bearing-surface i and edge I) are changed to correspond.

In Figs. 9 and 10 the axial line a is not in the same vertical plane with the head, but is located on one side, as shown. In these modifications the top and bottom of the head are cut away at suitable angle to allow of the necessary tilting movement, there being no contacts between the box B and the top and bottom of the head. The box is formed with out the curved surface 1'. The bearing-edges Z) are curved from the axial lines a as centers.

I have explained how the pitman is held again st lateral play in one directionviz., by the box Band I will now describe the means by which it is retained against lateral movement in the other direction, whether the knife be tilted or not. This means consists simply of a guide or retaining plate, G, which is securedto the cuttenbar so that it tilts with the knife. It is curved on its inner face from the point a as a center, and it is arranged in close proximity to or in slight contact with the pitman, or, preferably, a projection, 29, thereon. The guide G is of such length that its face will always be opposite the pitman or its projection no matter what the position of the cutter-bar and knife-head may be. The

adjacent portion of the pitman is preferably curved to correspond to the curved face g. The several Figs. '7, 8, 9, and 10 show the guide G having its face 9 formed to correspond to the position of the axial line a.

I claim 1. In combination with the pitman, the knife-head having vertical bearing -sides adapted to confine the pitman snugly, and having its upper and lower portions cut away from a central bearing-point to allow free tilting movement of the knife-head and knife, substantially as described.

2. In combination with the pitman, the hollow knife-head having the bearing-sides and the bearing-edges an, the upper and lower portions of the said head being cut away from the said edges to allow for the tilting of knife-head and knife, substantially as described.

3. In combination, the pitman, the knifehead having the curved edges, and the bearing-box having bearing-lugs, substantially as described.

4. In combination, the pitman, the bearingbox B, having the 1 curved surface 2', and the knife-head having bearing-sides and the edges to n, the upper and lower portions being cut away from said edges, substantially as described.

5. 1n combination, the pitman, the knifehead, and the bearing-box having retaininglugs, and an opening, m, extending partially through it to afford a bearing for the pitman, substantially as described. r 6. In combination with the pitman, the knife-head having vertical bearing-sides, and the bearing-box adapted to receive the end of the pitman and confined snugly by thebearingwalls of. the head, portions of said head being cut away above and below to allow free tilting movement of the knife-head and knife, substantially as described.

7. In combination, the pitman, the knifehead, and the bearing-box removably held by the pitman and head, substantially as described. a

8. In combination, the pitman, the knifehead constructed to permit tilting movement thereof up and down, and a guide Orretain ing plate having a curved face, g, adapted to allow said tilting movement, but to prevent displacement of the pitman during the same, substantially as described.

9. In combination, the pitman, the knifehead connected thereto in such a manner as to permit up-and-down tilting movement, a projection, 9, on the pitman, and a guideplate, G, having a face curved on the line of the tilting movement, substantially as described.

FRANK FORBES.

Vitnesses: v

D. F. MCCARTHY, J. W. MoCULLA.

IIO 

